what's the phenomenon called where you stop worrying about the previous pain you were having once other pain from another area comes around?

I feel like this Illness is more of a mental one more than it is a physical one than anything. Just a day ago I was in agonizing pain with my hands till my neuropathy took presence and now that’s an issue I can’t stop obsessing over fearing a neurological side of me is going off leading me to suspect for the worse of having something akin to MS because I am already an autoimmune wreck as is even tho I am 22.